Antistatic photographic film



Patented Dec. 13, 1938 UNITED STATES ANTISTATIG PHOTOGRAPHIC FILM AlfredD. Slack and Albert A. Young, Rochester,

This invention relates to and,more particularly, to film coatings.

This application is a of application Serial No.

N. Y., 'assig'nors Rochester, N. Y.,

PATENT OFFICE to Eastman Kodak Company, a corporation of New JerseyApplication March 1, 1938, Serial at. 193,302

12 Claims.

photographic film having anti-static continuation in part 41,417, filedSeptember 20, 1935, now Patent No. 2,1l8,059,'May 24, 1938.

A great the manufacture or use of account of charges on are known amountof trouble is caused during photographic (film on the accumulation ofthe electrical the film. These electrical charges as static andmay becaused by friction of the film against the rolls or other portions ofthe machines through or merely by contact with dissimilar 15 these andwhich it passes surfaces, other causes being known to those skilled inits manufacture. Static discharges in an unexposed film 'manifestthemselves by the formation of irregular streaks or lines caused by.

exposure of the emulsion at such portions. Static i charges are alsoobjectionable in finished film and cause an increase in the friction inthe film against the gates of a projector or other parts of themechanism through which the film passes.

Attempts t films have,

of applying to the surface of the film in order to increase.

0 overcome static in photographic for the most part, followed the linesconducting or hygroscopic materials its electrical conductivity.

The principal object. of

the present invention a is to provide an improved means for reducingfriction, in

common identity and thus some cases giving both surfaces a eliminatingthe static charges on a photographic film. .A further object is toprovide means photographic film sensitive emulsion.

for reducing the static in a base during coating of the A still furtherobject is to provide means for reducing static in a photographic filmduring passage through a camera Y or printing machine.

These objects are accomplished by the present invention by incorporatingin layers or on the surface of the of the film film, certain types ofsulfonated amides as described more fully hereinafter.

The materials which we use to prevent the I formation of static chargeson sulfonated amides having I the film consist of at least 8 carbonatoms in the molecule. These compounds are described in U. S. Patent No.1,932,180 and are sold under various trade-names, such as Igepon T andArtie Syntex T. The production of these materials forms no part of ourinvention.

' The compounds which we contemplate using are sul fonated compoundsformed from certain organic acid components by reaction with cer- 'thesensitive emulsion,

tain ammonia bases. such as taurine or taurine bodies. Among the organicacids which may be used are acids of vegetable origin containing 8 to 16carbon atoms, such as the. oils derived from soya bean, linseed,cotton-seed, peanuts, and 5 cocoanuts. These oils produce acids such asoleic, linoleic, capric, lauric, palmitic, stearic, etc. Lower fattyacids, such as acetic,.propion1c and butyric may also be used but thetotal number of carbon atoms in the resulting amide must 10 be at least8. The ammonia/bases used include taurine and taurine bodies, such asN-methyl,

'N-ethyl, N-butyl, N-cetyl, N-cyclohexyl, or N- in which R-CO denotes aradical of a fatty acid of vegetable origin, and

R1'=Hydrogen,

an aliphatic straight-chain radical, an aliphatic-aromatic radical, anaromatic radical.

In these taurides the sulfonic acid need not be in the free state asindicated in the above formula but the final products may be neutralizedby alkalies or organic bases of any kind which 40 do not adverselyaffect the photographic emulsion or film. Where we refer in the claimsto sulfonic derivative radicals it is to be understood that we intend toembrace the acid groups in the free state'as well as in the salt form.

We contemplate applying the taurides to the film in various ways todecrease or eliminate static. They may be applied (1) as a constituentof a gelatin sub-layer or as a coating over a gelatin sub-layer applied'to the base, (2) to on the back, over, or in or (3) to either surfaceof the exposed and developed film. The various ways of applying thesematerials, according to our invention, will now be described with par- Ithe finished film either ticular reference to the accompanying drawing.

As shown in Fig. 1 a film base 10 of transparent material such ascellulose nitrate, is coated with athin gelatin sub-layer H to which hasbeen added a sulfonated amide. The sensitive emulsion layer I2 is coateddirectly over this gelatin layer containing the amide. In themodification shown in Fig. 2, the base in is coated with the usualgelatin sub-layer I3 and directly over this is coateda solution of thesulfonated amide M. The sensitive emulsion I2 is coated directly on thislayer M. Fig. 3 illustrates a film base of a cellulose ester, such ascellulose nitrate, or a mixed ester, such as cellulose acetatepropionate l5, coatedwith a sub-layer I 6 which is a mixture of asynthetic resin and gelatin containing a sulfonated amide, on which iscoated the sensitive emulsion layer 12. The anti-static layer may alsobe coated as a separate layer in this case, as shown in Fig. 4, in whichI 1 represents a sub-layer comprising a mixture of a synthetic resin andgelatin having coated thereon a layer ll of gelatin containing 'asulfonated amide. The sensitive emulsion layer [2 is coated on thislatter layer. v

In the modification shown in Fig. 5 the base I5 of cellulose ester iscoated on both sides with a layer ll of gelatin containing a sulfonatedamide. The sensitive emulsion layers l2 are coated on these anti-staticlayers II. We have found that the static formed in a film coated on bothsides is materially'reduced when coating the second sensitive emulsionlayer, of one of the anti-static materials used, according to ourinvention, previously applied to the film.

In Fig. 6 there is shown a film consisting of a support l5 which may beof cellulose ester or other suitable material, coated with the usualgelatin sub-layer l3 and sensitive emulsion layer l2. The anti-staticlayer l4 consisting of the sulfonated amide solution is coated over thesensitive emulsion layer l2. As shown in Fig. '7, the emulsion layer hasbeen exposed and developed to form a silver image l9 therein and thefinished film is then coated with a layer I4 of a sulfonated amide.

The anti-static layer may be applied to the side of a film opposite tothat bearing the sensitized emulsion surface, as shown in Fig. 8, inwhich l represents a nitrate film support having the usual gelatin subI3 and emulsion layer l2 coated on one side thereof. The anti-staticlayer l4 consisting of a solution of. a sulfonated amide is coated onthe opposite side of the film support I 0.

The anti-static material may also be mixed with the sensitive emulsion,as shown in the modification of Fig. 9, in which I0 is the usual nitratefilm base and is coated with a sub-layer II which may consist of gelatinand a sulfonated I amide. On this sub-layer ll there is coated theemulsion layer 20 containing a sulfonated amide.

The amide may also be coated on one or both sides of asupport composedof a. cellulose mixed ester base having cellulose nitrate layers on bothsides. Supports of this combination type are used to secure advantagesnot present in a base composed of a single cellulose ester, and theanti-static material used according to our invention may be coateddirectly on this support, or may be applied in gel subs coated on it.The emulsion and backing layers are then applied in the usual manner.

Fig. 10 illustrates an anti-halation film backing containing asulfonated amide 'asflan antistatic material. As shown in Fig. 10, I isa film emulsion, it will obviously be applied in a solution which doesnot adversely afiect the sensitive emulsion. The anti-static materialsmay be .ap-

plied, for example, in an aqueous solution or 'a solution of ahydrocarbon, such as benzene or toluene or in a solution of an alcohol,such as methyl, ethyl, or higher alcohol, or in any other suitableorganic solvent, such as methyl Cellosolve. These organic solvents donot generally dissolve the salts of the amides, but the watersolublesolvents may be used in combination with water in solutions of thesalts, as indicated below.

The following specific examples will illustrate methods of applying theanti-static materials to the film, according to our invention, it beingunderstood that these examples represent preferred embodiments, but arenot to be considered as limiting our invention thereto.

Example I I sition:

G. Oleic acid amide of N-methyl sodium taurine 3 Water Methyl Cellosolve49 Methyl alcohol 24 Example II A film is made as in Example I, usingthe following backing solution:

G. Oleic acid amide of N-methyl sodium taurine- 3 Water 2Q Ethyllactate- 25 Methyl alc 52 Example III A film is made as in Example I,using the following backing solution:

Oleic acid amide of N-ethyl sodium taurine--- 1 Water 30 Ethyloxybutyrate Ethyl alcohol 54 (The formula for ethyl 'oxybutyrate is cm0H H-COQCzHa) Example IV A film is made as in Example I, using thefollowing anti-static coating solution:

G. Oleic acid amide of N-ethyl sodium taurine 3 Water 29 Isopropylalcohol 68 araar're It is to be understood that various types ofphotographic film base may be used in place of cellulose nitrate orcellulose acetate propionate, such as cellulose acetate, celluloseacetate butyrate, etc., and that our invention is not to be consideredas limited to the specific method of applying the anti-static materialsas described in our specification. The anti-static materials usedaccording to our invention may be-applied to photographic film innumerous ways not herein specifically desc bed. Our invention is to beconsidered as limited only appended claims.

What we claim is:

l. A photographic port carrying a photographic emulsion layer and ananti-static layer comprising a tauride containing sulfonic derivativeradicals corresponding to the formula wherein R-CO denotes a radical ofa fatty acid of vegetable origin, R3 is selected from the group havingthe formula of hydrogen, aliphatic straight-chain radicals,aliphatic-aromatic radicals, and aromatic radicals, and X is selectedfrom the group of hy drogen, alkali metals, and organic base radicals,in which tauride the total number of carbon atoms is at least eight.-

2. A photographic element comprising a support carrying a photographicemulsion layer and an anti-static layer comprising a tauride containingsulfonic derivativeradicals corresponding to the formula wherein R-COdenotes a radical of a fatty acid of vegetable origin, and R1 isan alkylradical, and X is selected from the group of hydrogen, alkali metals,and organic base radicals, in which tauride the total number of carbonatoms is at least eight.

3. A photographic element comprising a support carryin a photographiclayer and an antistatic layer co rising an oleic N-methyl tauride 0243051! in which X is selected from the group of hydrogen, alkali metals,and organic base radicals.

i. A photographic element comprising a transparent support carrying alight-sensitive emulsion layer and an anti-static layer comprising anoleic N-methyl tauride having the formula CH] C 7Hz3Co-N Y cimsom inwhich 7. is selected from the group of hydrogen, alkali metals, andorganicbase radicals.

'- 5. A photographic element comprising a transparent support carrying alight-sensitive emulsion layer and an anti-static'layer comprising atauride containing 'sulfonic derivative radicals corresponding to theformula 1 by. the scope of the element comprising a supwherein R-COdenotes a radical of a fatty acid of vegetableorigin, R1 is an alkylradical, and X is an alkali metal radical, in total number of carbonatoms is at least eight.

6. A photographic element comprising a transparent support carrying alight-sensitive emulsion layer and, between said support and saidemulsion layer, an anti static layer comprising a tau-, ride containingsulfonic derivative radicals corresponding tothe formula 2 wherein R-COdenotes a radical of a fatty acid of vegetable origin, 31 is an alkylradical, and X is an alkali metal radical, in which tauride the totalnumber of carbon atoms is at least eight.

7. A photographic element comprising-a support carrying-a photographicemulsion layer and, on the opposite side of said support, an anti-staticlayer comprising a tauride containing sulfonic which tauride thederivative radicals corresponding to the formula 1 i wherein R-CO-denOtes a radical of a fatty acid static layer comprising a tauridecontaining sulfonicderivative radicals corresponding to "the formula IR-GO-N r I c wherein R-CO denotes a radical of a fatty acid of vegetableorigin, R1 is an alkyl radical, and X is an alkali metal radical, inwhich tauride the total number of carbon atoms is at least eight.

9. A photographic element comprising a transparent support carrying aphotographic layer and, on the opposite side of said support, anantistatic layer comprising an oleic N-methyl tauride having the formulaOHa GnHrr-C O-N cimsotx in which X is selected from the group ofhydrogen, alkali metals, and organic base radicals.

10. A photographic element comprising a transparent support carrying alight-sensitive layer and, on the opposite side of said support, ananti-static layer comprising an oleic N-methyl tauride having theformula 0H3 CflHso-CON v \Q H BOaX in which X is selected from the groupof hydrogen, alkali metals, and organic base radicals.

'11. A photographic element comprising a transparent cellulcsicsupportcarrying a lightsensitive emulsion layer on one side thereof, andon the opposite side thereof, an anti-static layer comprising a compoundhaving the formula 10 sensitive emulsion layer on one side thereof, and

on the opposite side thereof, an anti-static layer comprising a compoundhaving the formula said compound being substantially only on the surfaceof the film support.

' ALFRED D. SLACK.

ALBERT A. YOUNG.

